Mr Dib, the new member for Lakemba, joined Labor's Class of 2015 at Parliament on Wednesday. He is one of 20 new MPs that the party hopes will make NSW Labor a major political force once more.

The new faces shared stories about their campaigns and the challenges of Twitter over tea and scones.

Luke Foley, who would later be returned as the party's leader, singled out the chatty Mr Dib as he tried to call his class to attention.

"I'm like the principal telling the rowdy boy in class to listen to the teacher," Mr Foley joked, before delivering a rallying address to his new MPs.

"This government will be held to account by you and by the enlarged Labor team in this Parliament," Mr Foley said.

"All of you campaigned for so long and so hard, I'm proud of all of you taking the fight to a first-term government with a popular premier in your communities, and winning seats back off the Liberals."

Labor won a 9 per cent statewide swing and is expected to gain at least 14 lower house seats when counting is finalised, giving it 34 seats to the government's predicted 54. Labor is expected to finish with seven upper house spots.

Mr Foley said Labor would ensure the government delivered on its "very large and extravagant" promises to the electorate.

"This government will be a better government because we have a stronger and more energetic opposition than we were able to muster after our very heavy defeat in 2011," Mr Foley said.

"We have, thanks to the people of NSW, unambiguously put the past behind us."

Mr Dib, the former principal of Punchbowl Boys High School, secured the safe Labor seat with a 14.5 per cent swing.

Jodi McKay, a minister in the former Labor government, won Strathfield and is expected to be elevated into the shadow ministry.

Other new Labor faces in Sydney seats include Greg Warren (Campbelltown), Julia Finn (Granville), Prue Car (Londonderry), Anoulack Chanthivong (Macquarie Fields), Hugh McDermott (Prospect), Steve Kamper (Rockdale) and Jo Haylen (Summer Hill).

New Labor MPs in regional NSW include Trish Doyle (Blue Mountains), Jenny Aitchison (Maitland), Kate Washington (Port Stephens), Yasmin Catley (Swansea), David Mehan (The Entrance) and David Harris (Wyong).

Later on Wednesday, Labor held its first caucus meeting of the new Parliament where Mr Foley was re-elected unopposed as the party's leader. Canterbury MP Linda Burney will serve as his deputy.

Adam Searle was appointed opposition leader in the upper house, with Walt Secord as his deputy.

Meantime, Greens candidate Adam Guise has conceded defeat in the nail-biting contest for Lismore. Nationals MP Thomas George has narrowly been re-elected, despite a swing against him of more than 21 per cent, largely driven by a community backlash over coal-seam gas.

It leaves the Greens with three lower house seats.

Two lower house seats remain in doubt: East Hills, which the Liberals are likely to retain, and Gosford, which Labor is expected to win.